CA2131649A1 - State-of-the-art radiotelephone installation - Google Patents

Abstract

Abstract Improved radiotelephone installation In a radiotelephone installation comprising at least one fixed terminal connected to a predetermined telephone communication network and comprising at least one radiofrequency-terminal channel suitable for ensuring radio intercommunication with at least one radiofrequency-station channel of an autonomous station , in the event of a quantity of quality lower than the threshold, the processing means-terminal or station are liable to impose a correction of the reception or station clock.

Description

2 1 3 1 6 4 9 Improved radiotelephone installation The invention relates to radiotelephony.

It finds a particular application in phones without second generation ~ CT2 such as those offered by the operator FRANCE TELECOM under the Brand.
registered "POINTEL" or "BI-BOP".

Radiotelephone installations are already known which include at least one fixed terminal connected to a network of. .
predetermined telephone communication at including minus a radiofrequency-terminal channel capable of ensuring radio intercommunication with at least one channel radio frequency of an autonomous station, said channel.
radiofrequency-terminal or station including - transmitter-terminal or post means suitable for transmitting binary data at a transmission frequency terminal or station set on a predetermined reference-terminal clock or station ~
born, 2S - receiver-terminal or station means suitable for sample-binary data to a terminal reception clock or position whose phase is subject to the transitions of binary data received, the transmitter-terminal or station means and the receiver-terminal or station means being specific to ensure the transmission of binary data according to a screening predetermined alternating time, means of measurement - terminal or station suitable for measuring a quantity of quality of reception of binary data, and 3S to periodically compare said quantity with a predefined threshold finished ~, and - own terminal or post processing means, presence of a quantity of quality greater than or equal to 40 threshold, to periodically validate the servo of the clock ~ ~;

;,.,. :: ~.

2 ~ 31 ~ 9 -?
~: 2 reception terminal or station to correct the phase difference between said reception or terminal clock and the transitions of binary data received. ; `; ~

In the presence of a quantity of lower quality of reception at the threshold meaning that data reception is bad ~
se, the terminal or post processing means no longer validate servo-control of the reception or terminal clock, which generates a drift of said reception-terminal clock -or post with respect to said data transitions binaries received. ~ -When the measured reception quality quantity becomes again greater than or equal to the threshold, the terminal processing means 15 or post resume validation of the servo of; `~ ~
reception or terminal clock to correct ~ i again the phase difference between said reception clock ~
terminal or post and binary data transitions received. ;
In practice, in the event of good reception, the control in phase is performed automatically at the start of the frame ception, for example at each reception frame, said asser- - ~
screwing being terminated by an interrupted siynal addressed 25 to the terminal or post processing means. ; ~

The value of the phase control is fixed, for example 1 / 16th of a bit in case of drift or 0. The sign of the slave ~
sement is chosen according to the direction of drift determined by ~ ~ -comparison of the rising edges of the reception clock-bollard or post with rising or falling edges of ~
transitions of binary data received. - ;;

It should be noted that, in the case of a higher drift at half a bit, the front-to-front comparison can lead to offset synchronization of the reception clock terminal `~
or station with transitions of binary data received at least one bit. ~ -2131 ~ 49 `3 such a shift has the disadvantage of inevitably generating incorrect processing of binary data received.

L! invention provides a solution to this problem.
Thus, the invention aims to provide a radio installation:
phonic in which the drift of the reception clock ~ ion--terminal or station in relation to data transitions ~ - ~
binary rec ~ ues is corrected to avoid the shift of one or several bits for correct data processing.

- According to an essential characteristic of the invention, this ~ ~ -result is obtained by imposing a clock correction reception terminal or station in case of quality quantity below the threshold (i.e. when the quality of the data reception is poor).

In practice, the correction imposed comprises a plurality of elementary corrections imposed at a chosen rate and in a chosen direction.

Advantageously, the parameters of the imposed correction such as that the cadence and the direction are determined according to elementary corrective values of the phase control 25 of said reception or terminal clock made in ~ `
presence of a quantity of quality greater than or equal to threshold and memorized beforehand for a number of frames reception terminal or predetermined station.

In practice, the parameters of the imposed correction are determined based on the algebraic sum of values elementary corrective measures of the phase control as well previously memorized.

According to another aspect of the invention, the radio frequency channel terminal also includes ~

- radiofrequency-terminal means capable of modulating the binary data emanating from the transmitter-terminal means in 2131 ~ '~ 9 ~ 4 radio frequency signals and to demodulate the radio signals ~
quence received in binary data,; ; ~ ;; .

- audio-terminal means suitable for coding and decoding bidirec ~
speech in binary data and to process signaling data, - a line interface for connecting the means. ~. .
audio-terminal to the telephone communication network, and ,. ", ~ ~.." ~, - control means-terminal suitable for assembling / disassem ~
- block in the form of frames the data exchanged between::
radiofrequency-terminal means, audio-terminal means and the - ~
terminal processing means, said processing means terminal being suitable for controlling the control means-terminal ~

According to a preferred embodiment of the invention, the path `.
radio frequency of each autonomous station also includes: .-- radio-station means suitable for modulating the binary data emanating from the transmitter / post means in. ~.
radio frequency signals and to demodulate the radio signals quence received in binary data, - audio-post means suitable for coding / decoding speech in binary data and convert / deconvert data ~:
binary in analog data, and - post control means suitable for assembling / disassembling: ~
block under ~ frame elm the binary data exchanged between the radio-station means, the audio-station means:
and post processing means, said milking means ~
ment-poste being able to control the means of control-post.
In practice, at the start of each terminal-reception frame or post, the receiver-terminal or post means deliver a interrupt signal to terminal processing means or ~ - -: '..:'' ~ 1316 ~ 9 . .

extension to signal said start of reception frame-terminal or post. ~ ~ --: '' ~ ' Furthermore, at the end of each reception-terminal frame or 5 station, the measuring means-terminal or station deliver a - ~
interrupt signal to the terminal processing means or -pcste when the measured quality quantity changes from one - ~
value below the threshold to a value above the threshold ~;
and reciprocally.
Preferably, the frequency of the reference-terminal clock is 500 Hz and the frequency of the reception clock ~ terminal-terminal ~;
or slave station is 72 kHz.

Advantageously, the post-reference clock is the clock reception-slave station.

According to one embodiment of the invention, in the event of quality quantity below the threshold, each correction elementary of the imposed phase difference is + or - 1/16 bit for a reception-terminal or post frame, and by example carried out at the start of said reception-terminal frame or post. ~; ~

According to one embodiment of the invention, in case of good reception, the value of an elementary servo in phase is + or - 1/16 bit or 0 depending on the direction and the value of the derivative.

Advantageously, the terminal or post processing means are - ~
suitable for reading the current corrective value of the servo ~
elementary in phase in response to an interrupt signal tion, and to store the value thus read.

35 Other characteristics and advantages of the invention - ~
will appear in the light of the detailed description below and drawings in which:

21 31 G ~ 9 - Figure 1 shows a schematic diagram of a radio installation of the POINTEL type of art prior, - Figure 2 shows a schematic diagram of a fixed radio terminal of the prior art, - Figure 3 shows a schematic diagram of a station autonomous radio of the prior art, , ~ ~ "~ - ~. ,,"
- Figure 4 schematically shows the time framing alternating binary data transmitted / received according to art previous, ~:

- Figure 5 shows schematically the settings and Pmission and reception clocks on the terminal side according to the prior art, - Figure 6 schematically shows the settings and 20 transmission and reception clocks on the station side `
autonomous according to the prior art, ':
- Figure 7 schematically illustrates the servos `~
automatic reception or terminal reception clock on 25 transitions of binary data received in the event of magnitude of: ~
quality greater than or equal to the threshold in accordance with art prior, - Figure 8 schematically illustrates the drift of the clock receiving terminal or post in relation to the transitions of binary data received in case of quality quantity below the threshold according to the prior art, - Figure 9 schematically illustrates the drift of the clock of reception terminal or post with respect to transitions of binary data received in case of quality quantity below the threshold and the automatic controls the reception or terminal clock on the transitions of binary data received in case of quantity of superior quality `` '. ~ ~ 2l3l6 ~ g . 7 below the threshold leading to correct treatment of given according to the prior art, - the f igllre 10 i ~ strG schematically the drift of the clock-reception box terminal or post in relation to transitions binary data received in case of quality quantity below the threshold and the automatic controls the reception or terminal clock on the transitions of binary data received in the event of a higher quality quantity below the threshold leading to incorrect processing of data in accordance with the prior art, :
- Figure 11 schematically illustrates the controls automatic reception or terminal reception clock on transitions of binary data received in the event of magnitude of quality above the threshold con ~ ormément to the prior art and the correction imposed in the event of a quantity below the threshold;
according to the invention,. ~ ;.
,. . .
- Figure 12 schematically illustrates the controls automatic at each reception frame of the clock terminal or post reception on data transitions binaries received in the event of a quality quantity greater than. ~. :
threshold according to the prior art, - ~
- Figure 13 schematically illustrates the controls.
automatic every two clock reception frames receiving terminal or post on data transitions.
binaries received in the event of a quality quantity greater than threshold according to the prior art, .
- Figure 14 schematically illustrates the storage of corrective values of the controls for a period predetermined according to the invention, - Figure 15 schematically illustrates the controls au ~ omatic each frame interrupted by a freeze of these:
enslavements in which corrections are imposed every two frames, followed by a thaw in which are :

21316li9 ~:

carried out automatic slaving every frame according to the invention, - Figure 16 schematically illustrates the controls automatic every two frames interrupted by a freeze these enslavements in which corrections are imposed followed by a thaw in which slaves are made automatic frames every frame, then slaves two automatic frames according to the invention, and - Figures 17 and 1i3 schematically illustrate the function processing of the terminal or post processing means according to the invention.
The drawings mainly include elements of certain character. As such, they will not only to better understand the detailed description below after but also contribute, if necessary, to the definition of the invention.
. . .
With reference to FIG. 1, we will very briefly describe the ~;
known structure of a radiotelephone installation of the type of that including cordless telephones of secon ~ e 25 generation (CT2) such as those offered by the operator ~ - ~
FRANCE TEI.ECOM under the trademark "POINTEL" or "BI-BOP".

Autonomous PA stations, such as telephone handsets `~ -portable, capable of remote mutual cooperation 30 per radio channel with at least one fixed BFR radio terminal. The - ~
radio exchanges between the autonomous stations and the fixed terminal; ~ `
are governed by a standard called "CAI" for Common Air Interface.
~ '' ~ `~, ..
The fixed terminal BFR is connected to a connection unit of URL bollards capable of managing a plurality of fixed bollards BFR.

~ 2 ~ 316 ~ 9 .. `, ~ g. .
Fixed terminal can be directly connected to channels of the PSTN switched telephone network. In that case the URB unit which manages the BFR terminal is not connected to these c nals.
On TRS digital signaling channels, operating packet operation, such as the TRANSPAC network (brand filed), the various connection units are connected URB as well as other constituents of the POINTEL network 10 (not shown). ..
-; ~.; ~ ' Referring to Figure 2, the BFR terminal includes a plurality of VB radiofrequency channels individualized in VB1.; ~.
at VBN. : -~:
A UCB control unit, common to all channels of the terminal, is connected to the URB connection unit which manages the. ~:
BFR terminal.

20 In practice, each radiofrequency channel includes ~

- a CANB multi-channel coupler allowing the coupling of radio channels to an ANB antenna; ~; ~

25 - EMB terminal-emitter means suitable for transmitting:: ~
binary data at a terminal transmission frequency set to;:
a predetermined reference-terminal clock;

- RRB terminal-receiver means suitable for sampling binary data to a terminal reception clock whose phase is slaved with binary data transitions received; the transmitter-terminal EMB means and the reception means:
RRB terminal teurs being suitable for ensuring the transmission of binary data according to an alternating time framing predetermined;

- means dP measurement-terminal MMB suitable for measuring a ~:
magnitude of ~ uality of reception of binary data and;:
comparing said quantity with a predetermined threshold; and .

.`. 2 ~ 3l64 ~
"10 - own UCVB terminal processing means, in the presence of:
of a quality quantity greater than or equal to the threshold, at - - ~
periodically validate the clock control of:
reception-terminal to correct the phase difference between said reception-terminal clock and data transitions binaries received; ::
:
- RAB radio frequency means capable of modulating the data binaries emanating from the transmitter-terminal means in signals radio frequency and demodulating the radio frequency signals received in binary data; ~.

~ AUB audio-terminal means suitable for coding and decoding bidirectionally speech into binary data;

- an ILB line interface for connecting the means audio-terminal AUB to the PSTN telephone communication network;

- CTB terminal-control means suitable for assembly / disaster-20 appear in the form of frames the data exchanged between the :: ~ -RA-terminal radiofrequency means ~, audio-terminal means: - ~ `
AUB and the UCVB terminal processing means, said means of: ~ :: ..;
processing-terminal UCYB being suitable for controlling the means of . control-terminal CTB. ; ~
Advantageously, the means EMB, RRB, CTB are grouped in a BMLB block.

With reference to FIG. 3, an autonomous station PA comprises - an ANP antenna device, - RRP receiver-station means suitable for sampling binary data to a post office reception clock whose phase is slaved with binary data transitions received, - EMP station-transmitter means suitable for transmitting binary data at a transmission frequency set to 2 ~ 31 ~ 9 . .
.. 11 the post-reception clock, the EMP station-transmitter means and the RRP receiver-station means being suitable for ensuring:
transmission of binary data according to a time framing erl predetermined alternation, . ~ -- MMP post-measurement means suitable for measuring a q quality of reception of binary data and to compare said quantity with a predetermined threshold:

- UCP post processing means capable of comparing periodically said quantity at a predetermined threshold, and presence of a quantity of quality greater than or equal to threshold, to periodically validate the clock control - ~
reception to correct the phase difference between: ~ ~:
reception-terminal clock and data transitions binaries received, : ': "' ~
- radio-station means capable of modulating them;
binary data emanating from the post-transmitter means in radio frequency signals and to demodulate the radio signals quence received in binary data, - AUP audio-post means suitable for coding / decoding the: ~
speech into binary data, and convert / deconvert them 25 binary data in analog data, ~ -- CTP station control means suitable for assembly / de- ~
collect the binary data exchanged in the form of frames: ~.
between the CERP radio-station resources, the resources. :
AUP audio-post and UCP post-processing means, said UCP post processing means being specific to pilot the BMLP post control means. .

Peripherals such as a CLA keyboard, a device display ~ CR and its CONT controller complete the environment UCP post processing means.

Advantageously, the EMP, RRP and CTP means are grouped together in a BMLP block.

21316 ~ 9 Referring to Figure 4, the exchange of data between the fixed terminal and an autonomous station is performed according to a screening alternating time called "ping pong" since when the terminal sends the item re, coit and vice versa.

In practice, the bit rate according to the CAI standard in multiplex 1.4 for example is 144 bits every 2 ms with 68 bits for the transmission of a frame; 68 bits for receiving a frame; 3.5 bits for side transmit / receive interval terminal and 4.5 bits for the reception / transmission interval terminal side.

With reference to FIG. 5, the emitter-terminal means EMB
transmit binary data at a transmission frequency ~
FEB terminal set on a reference clock-HRR terminal.
.. ,, ..:
, .. ~
For example, the frequency of the reference clock-terminal HRR
is 500 Hz.

CALB timing of the FEB frequency on the HRR clock is fixed and configurable.

RRB receiver-terminal means ec: haunt data binary to a reception clock ~ HRBA terminal whose phase is slaved ASS with transitions of binary data transmitted at the frequency of 72 kHz for example.

Referring to Figure 6, the EMP station-transmitter means transmit binary data at a transmission frequency ~
FEP station set on the reception clock-slave station HRPA.

CALP time setting of the FEP frequency on the clock HRPA is fixed and configurable.
RRP receiver-receiver means sample data binary to a reception clock ~ HRPA station whose phase is slaved ASS with transitions of binary data received transmitted at the frequency of 72 kHz.

31 ~ 4 ~
13 '~
Referring to Figure 7, the periodic servos and at ~ omatic ASS of the reception clock terminal or post -HRBA or HRPA are performed on data transitions binaries received in the case of a quality quantity greater than:
threshold to correct the possible phase difference between these two signals. ~; ~

It should be noted that the binary data is transmitted at a FEPD or FEBD frequency corresponding to the frequency of transmission ~
sion-post or ~ adorns FEP or FEB of the transmitting means or EMP or EMB terminal offset by a time due to the crossing of the `~
- radio-station or terminal means in transmission. Likewise, FRPD or FRBD frequencies of the data received at the inputs of the BMLP or BMLB blocks, correspond to the FEBD or FEPD frequencies offset by a time due to the crossing of the radiofrequency means post office or terminal on reception.

In practice, the correction of the phase difference when the ~ /
data reception is good, is performed periodically at the start of the reception frame, for example each time me-reception.
. , The value of an elementary periodic phase control ASS is fixed, for example 1 / 16th of a bit in case of drift or - ~ -0. The sign of this elementary enslavement is chosen according to the direction of drift which is determined by comparison rising edges of the reception or terminal clock with rising or falling edges of transitions binaries received.
With reference to FIG. 8, in the event of poor reception, the;
drift from reception or terminal clock relative to transitions of binary data received can be important.
Indeed, in the presence of a quantity of quality lower than the threshold signifying that data reception is poor, the terminal or post processing means no longer validate or "freeze" the elementary and periodic servo ASS of ~ `` ~ ' '213 ~ 649 the clock, which causes the clock to drift reception-terminal or post in relation to said transitions of binary data received.

It should be noted that at the end of the reception frame, the measuring means - terminal or post are capable of delivering an ITG1 interrupt signal in favor of the means of processing-terminal or post to signal an instant when the reception quality becomes poor and should be freeze the periodic servo of the receiving clock tion. This gel lasts as long as the reception quality remains mauvalse.

Similarly, in Ein of the reception frame, the means of measurement-terminal or post may signal ITG2 interruption in favor of terminal processing means or post to report a time when the quality of reception becomes good and it is then advisable to thaw the slave ~
periodic reception clock. This thaw lasts as long as the reception quality remains good.
. : ..
In reference to FIG. 9, the drift of the clock of reception terminal or post in relation to transitions of binary data received in case of quality quantity below threshold occurs between ITG1 and ITG2 indicating to the terminal or post processing means respectively a g21 and a thaw of elementary and periodic enslavement ASS.
~. ~. ,, ~. .
In the event of a quality quantity greater than the threshold, it is say after ITGZ, the terminal or post processing means resume validation of the ASS servo with a first ASS1 control and a last ASS2 control for the drift recovery operation.
The result of the basic servos ASS1 to ASS2 is here satisfactory insofar as the resynchronization of reception clock with data transitions binaries compensates for the drift.

~ 23l6 ~
~ ~;
. . 15 -:

Referring to Figure 10, we find the DEV drift described with reference to Figure 9.

5 The result of the basic servos ASS1 to ASS2 is; ~
here bad as far as the resynchronization of reception clock with data transitions: ~
binary does not compensate for drift. ;

Indeed, in the case of a drift greater than half a bit, the front-to-front comparison here leads to a synchronization shifted from the reception-terminal clock with the transitions of binary data received by at least one bit.

Such a shift inevitably generates processing incorrect binary data re, cues.

Referring to Figure 11, we find the DEV drift described with reference to Figures 9 and 10.
To solve the mentioned lag problem above, it is planned to impose a basic correction and periodic CIP1 to CIP2 in the event of a magnitude less than ~ ~
threshold, i.e. during the interval ITG1 to ITG2. i In practice, the correction imposed comprises a plurality of elementary CIP corrections made at a chosen rate FT and in a chosen direction.

Advantageously, the parameters of the elementary corrections imposed CIP1 to CIP2 are chosen according to the values basic corrective measures of the servo in the ASS phase of said terminal or post reception clock carried out when the quality quantity is greater than or equal to the threshold and memorized beforehand for a number of frames of reception of predetermined terminal or post. ~.

In practice, the parameters of the elementary corrections imposed are chosen according to the algebraic sum of 21 31 6 ~ 9 ~ ~
, ~

elementary corrective values of the phase control thus previously memorized.

After ~ s ie dege ~ c that is to say after ITG2), the means of 5 processing resume validation of the servo ~ x ~
periodic and automatic ASS.

Referring to Figure 12, the basic servo ~ -and automatic ASS are performed on each frame reception of the reception or terminal clock on the transitions of binary data received in case of quantity of superior quality lower than the threshold.

In practice, the basic ASS servo is terminated by an IT interrupt signal issued for the benefit of treatment.

This interrupt message is made here at the beginning of each reception frame.
With reference to FIG. 13, the elementary servos; ~ -and automatic ASS are produced every two frames reception of terminal or station reception clock (AT = 2).

With reference to FIG. 14, the memorization of the values corrective of the basic servos ASS1 to ASS7 takes place for a predetermined period, here for 7 reception frames between L1 and L2.

This memorization consists in reading LEC the value of the asser ~
ASS elementary screw after the IT interrupt signal generated after each elementary ASS servo.

These are the processing means that read this ASS `value -in response to the IT signal.

It should be noted that in this example according to the invention, ASS1 and ASS7 elementary control systems are implemented and read at each reception frame (AT = 1).

Referring to Figure 15, the periodic servos ASS performed at each frame are interrupted by an ITG1 gel and are followed by periodic imposed corrections according to the invention, themselves interrupted by an ITG2 thaw followed automatic controls all the frames.

In this example, the imposed CIP corrections are made during the freeze (here between ITG1 and ITG2) both reception frames according to the invention.
It is thanks to a predetermined ATG message emanating from the means processing after the ITG1 interrupt signal that this correction imposed takes place here every two frames and in the direction specified by the ATG message.
The generation of the ATG message is carried out as follows.
The ATG message is programmed in a register belonging to the CTP or CTB post or terminal control means.

It specifies the direction and the FT cadence of the elementary corrections.
silos imposed CIP during a freeze period.

The AT1 message is generated in a substantially similar manner.
re. It indicates the cadence of elementary enslavements (all frames for AT1).

Referring to Figure 16, the automatic controls ASS are first produced every two frames (before ITG1), a freeze is made (between ITG1 and ITG2) with elementary corrections imposed CIP every two frames in the direction indicated by ATG, then of the enslavements ASS elementary and automatic are performed every AT1 frames as specified by the AT1 message and finally all the two frames as specified by the AT2 message.
Referring to Figure 17, the operation of the means of terminal processing to acquire the correct values ~
ves is as follows.

21 31 b '4 9 ...

First (step 10), the terminal processing means or post initialize the AT cadence of the basic servo shutters ASS to 1, that is to say for all the frames of reception.
In step 12, the terminal or post processing means are waiting for an ITG1 interrupt signal signaling the freeze of the servo or an IT signal signaling the start of the current frame.

During step 14, in the presence of an IT signal indicating the - start of a frame, it is planned to read the value of the assert-screw ASS1 and store the value thus read in a register rl for the current frame (rl here is equal to --1/16 bit, 0 or +1/16 bit) (Figure 16).

During step 16, the processing means-terminal or station are waiting for an IT signal or an ITG1 signal.

During step 18, in the presence of an IT signal signaling the next frame, it is planned to read the value of the servo ASS2 and store the value thus read in a register r2 for the next frame (figure 16).

During step 20, it is planned to compare the values of the registers rl and r2.

In the event of a positive comparison, it is planned to revert to step 16. This positive comparison means that the asser ~
ASS1 elementary screwing of the current frame is identical to the elementary servo ASS2 of the following frame In the event of a negative comparison, it is planned to move to step 22 in which two variables R and N are initialized set to 0.

During step 24, the processing means-terminal or station are waiting for an IT signal or an ITG1 signal. ; ~

2t316 ~ 9 : "
"~ 19. ~ ~ /
In the presence of an IT signal (step 26), provision is made to increase lie variable N by 1, and increment the variable R of r, r being the value of the enslavement.

5 During step 28, the variable N is compared to a threshold ~ `
predetermined corresponding to the number of frames relative to the reading time Ll-L2 described with reference to the figure 14. ...

In the event of a negative comparison, it is planned to revert to step 24, while in the case of a positive comparison, it is planned to go to step 30. ~ `

During step 30, the processing means-terminal or station 15 are waiting for an IT or ITG1 signal. ~

During step 32, in the presence of an IT signal, provision is made: ~; to calculate the AT rate of the elementary servos ASS and FT the rate of the elementary corrections imposed during a period of frost.

The calculation of AT and FT is a function of the corresponding R / N ratio.
according to the ratio between the algebraic sum of the slaves:
ASS elementary and periodic elements and the number of frames `
of the reading period L1-L2.

ha value of the R / N ratio makes it possible to determine the AT and FT
optimal.

In practice, AT is an integer value 1, 2, 3, 4, ...
strictly less than R / N. :;

As for FT, this is an integer, the most close to R / N.

For example, if R / N = 7.8, then FT = 8.

If R / N = 16, then FT = 16. ~:.

., ..,. ,,.,,. ., .. ,, ~

213 ~ 649 An imposed elementary correction CIP of period FT a by example as value +1/16 bit or -1/16 bit.
~.
It should be noted that in the presence of an ITG1 signal indicating the freezing of enslavements because of the poor quality of reception of data (steps 12, 16, 24 and 30), it is planned (step 40) to wait for an ITG2 signal indicating the thaw (good reception).

In the presence of an ITG2 signal, it is planned to return to step 10. ~ - ~

After this reading period and the calculation of R / N, it is planned to make imposed corrections in the event of frost according to the invention (Figure 18 ~.

During step 100, the processing means-terminal or station are waiting for an ITG1 signal.
~: ~
While waiting, the terminal processing means or post validate the elementary and periodic servos ques ASS, with saving AT in an AS variable.
'~: ": ~
During step 105, the terminal or station processing means are waiting for an ITG2 signal. They position the variables A for advance and D for delay relating to corrections imposed CIP. It is the ATG message which indicates the ~ ~ -direction A or D and the number FT of frames. In practice, FT is copied to AT. Depending on the direction of correction, the variables A and D are positioned at 0 or 1.

In the presence of an ITG2 signal indicating the deyel of the slaves ~
ASS periodic period, it is planned to return to AT = 1 (step 112) and set the variables A and D to 0.
During step 114, the processing means-terminal or station are waiting for an IT or ITG1 signal.
:: -'; -~.
. ::

3 ~

In the presence of an IT signal (step 116), provision is made to read.
the value of the ASS servo and to store said value in the register rl.

During step 118, the processing means-terminal or station are waiting for an IT or ITG1 signal. :

In the presence of an IT signal (step 120), it is planned to read the new value of the ASS servissem ~ nt and store said value in the register r2.

During step 122, provision is made to compare the values rl and r2.

In the event of a negative comparison, it is planned to revert to step 118, while in the case of a positive comparison, it is planned to initialize the variable AT again to the value AS
backup. ;; ~

''''.'~';"''''''"'"' ~. '

Claims (16)

1. Radiotelephone installation comprising at least one fixed terminal (BFR) connected to a telephone communication network predetermined route (RTC) and comprising at least one route radiofrequency-terminal (VB) capable of ensuring intercommuni-radio cation with at least one radio frequency channel-station of an autonomous station (PA), said radiofrequency channel--terminal or station including:

- transmitter-terminal (EMB) or post (EMP) means specific to transmit binary data at a terminal transmit frequency (FEB) or post (FEP) set on a reference-terminal clock (HRR) or predetermined position (HRPA), - receiver-terminal (RRB) or post (RRP) means specific to sample binary data at a reception clock tion-terminal (HRBA) or station (HRPA) whose phase is controlled with the transitions of the binary data received, the means terminal transmitters (EMB) or post (EMP) and the receiving means terminal (RRB) or post (RRP) teurs being able to ensure the transmission of binary data according to a time framing in predetermined alternation, - terminal measurement means (MMB) or station (MMP) specific to measure a quality quantity of data reception binary, and to compare said quantity with a predeter threshold-mined, and - terminal (UCVB) or post (UCP) processing means clean in the presence of a higher quality quantity or equal to the threshold, to be validated periodically, the control of the reception or terminal clock (HRBA or HRPA) for correct the phase difference between said reception clock--terminal and the transitions of the binary data received, characterized in that in the case of a quantity of inferior quality lower than the threshold, the terminal processing means (UCVB) or post (UCP) are likely to impose a correction (CIP) of the reception or terminal clock. 2. Installation according to claim 1, characterized in that than the imposed correction (CIP) of the reception clock--terminal or station includes a plurality of elementary corrections shutdowns at a selected rate (FT) and in one direction selected. 3. Installation according to claim 1 or 2, characterized in that the parameters of the imposed correction such as the cadence (FT) and direction are determined according to elementary corrective values of the phase control (ASS) of said reception-terminal clock or set station killed when the quality quantity is greater than or equal at the threshold and memorized beforehand for a number of reception frames-terminal or predetermined station. 4. Installation according to claim 3, characterized in that that the parameters of the imposed correction (CIP) are determined based on the algebraic sum of values elementary corrective measures of phase control (ASS) thus previously memorized. 5. Installation according to one of the preceding claims, characterized in that the radio frequency channel of the terminal further includes:

- radiofrequency-terminal means (RAB) capable of modulating the binary data from the emitter-terminal means (EMB) in radio frequency signals and to demodulate the radio signals quence received in binary data, - audio-terminal means (AUB) suitable for coding and decoding bidirectionally speech into binary data, - a line interface (ILB) for connecting the means audio-terminal (AUB) to the telephone communication network (RTC), and - terminal control means (CTB) suitable for assembly / disassembly collect data exchanged between frames radio-terminal means, audio-terminal means (AUB) and the terminal processing means (UCVB), said means of processing-terminal (UCVB) being able to control the means of control-terminal (BMLB). 6. Installation according to one of the preceding claims, characterized in that the radio-frequency channel includes in addition:

- radio-station means (RAP) capable of modulating the binary data emanating from the transmitter-post means (EMP) in radio frequency signals and to demodulate the radio signals quence received in binary data, - audio-post means (AUP) suitable for coding / decoding the speech into binary data, to convert / deconvert binary data into analog data, and - post control means (CTP) suitable for assembly / disassembly collect the binary data exchanged in the form of frames between the radio-station means (RAP), the means audio-post (AUP) and post-processing means (UCP), said post processing means (UCP) being specific to pilot the means of post control (CTP). 7. Installation according to one of the preceding claims, characterized in that at the start of each reception frame--terminal or station, the receiver-terminal or station means an interrupt signal (IT) to the means of terminal or post processing (UCVB or UCP) in order to report said start of reception frame-terminal or post. 8. Installation according to one of the preceding claims, characterized in that at the end of each reception frame--terminal or post, the measuring means-terminal or post are likely to issue an interrupt signal (ITG1 or ITG2) to the terminal or post processing means (UCVB or UCP) when the measured quality quantity changes from one value below the threshold to a value above the threshold and reciprocally. 9. Installation according to one of the preceding claims, characterized in that the frequency of the reference clock terminal frequency (HRR) is 500 Hz. 10. Installation according to one of the preceding claims, characterized in that the post reference clock is the slave reception-post clock (HRPA). 11. Installation according to one of the preceding claims, characterized in that the frequency of the reception clock tion-slave terminal (HRBA) is 72 kHz. 12. Installation according to one of the preceding claims, characterized in that in the case of a quantity of inferior quality lower than the threshold, each elementary correction of the deviation of imposed phase (CIP) is + or - 1/16 bit. 13. Installation according to claim 12, characterized in what in case of bad reception, the elementary correction phase difference (CIP) is imposed at the start of the reception-terminal or post. 14. Installation according to one of the preceding claims, characterized in that in the case of a quantity of superior quality greater than or equal to the threshold, the value of a servo elementary (ASS) in phase is + or - 1/16 bit or 0 depending on the direction and the value of the drift. 15. Installation according to claim 14, characterized in what phase lock is done at the start of the reception frame - terminal or post and terminated by a signal of interruption (IT) with regard to the terminal processing means or post. 16. Installation according to claim 15, characterized in what the terminal or post processing means (UCVB or UCVP) are suitable for reading the current corrective value of the assert-elementary screwing in response to the interrupt signal and to store the value thus read.